/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package cn.edu.seu.cose.hobbysharing.servlet;

import cn.edu.seu.cose.hobbysharing.tool.XMLTranslator;
import cn.edu.seu.cose.hobbysharing.bean.Hobby;
import cn.edu.seu.cose.hobbysharing.bean.HobbyList;
import cn.edu.seu.cose.hobbysharing.dao.HobbyDao;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Collection;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author hp-2
 */
@WebServlet(name = "HobbyOperator", urlPatterns = {"/myhobby"})
public class HobbyOperator extends HttpServlet {
    String operation;
    String userid;
    String hobbyName;
    String hobbyId;
    PrintWriter out;
    /**
     * Processes requests for both HTTP
     * <code>GET</code> and
     * <code>POST</code> methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected boolean preprocessRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            userid = request.getParameter("user");
            hobbyName = request.getParameter("name");//for adding hobby, type: String
            hobbyId = request.getParameter("id");//for deleting hobby, type: Long
            operation = request.getParameter("operation"); //expected value: add/delete
            out = response.getWriter();
            if(userid==null) {
                return false;
            }
            return true;
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP
     * <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    //根据userid查找用户兴趣，response返回HobbyList转制的xml文件
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/xml;charset=UTF-8");
        if(!preprocessRequest(request, response)){
            response.sendError(400);
            return;
        }
        try {
            HobbyDao hd = new HobbyDao();
            Collection<Hobby> hc = hd.getHobbiesByUser(userid);
            HobbyList hl = new HobbyList();
            hl.setHobby(hc);
            out.print(XMLTranslator.objToXML(hl));
        } catch(Exception e){
            response.sendError(500,e.getMessage());
        }
        finally {            
            out.close();
        }
    }

    /**
     * Handles the HTTP
     * <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    //添加或删除用户兴趣，response返回字符串"done"
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/plain;charset=UTF-8");
        if(!preprocessRequest(request, response)||operation==null){
            response.sendError(400);
            return;
        }
        try {
            HobbyDao hd = new HobbyDao();
            if(operation.equals("add")){
                //根据name添加兴趣
                if(hobbyName==null) {
                    response.sendError(400);
                    return;
                }
                hd.addHobby(userid,hd.newHobby(hobbyName));
            }else if(operation.equals("delete")){
                //根据id删除兴趣
                if(hobbyId==null){
                    response.sendError(400);
                    return;
                }
                hd.removeHobby(userid,Long.valueOf(hobbyId));
            }
            out.print("done");
        } catch(Exception e){
            response.sendError(500,e.getMessage());
        }
        finally {            
            out.close();
        }
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
